Scientists in California are hoping to use your smart phone to solve a cosmic mystery. They're developing an app to turn your phone into a cosmic ray detector. If enough people install the app, the scientists think they'll be able to figure out once and for all what's producing the very energetic cosmic rays that occasionally hit the Earth.

...Scientists know these high energy particles exist. The first one was detected by researchers in New Mexico in 1962, and more have since been seen at the Pierre Auger Observatory in Argentina. But nobody knows what's producing them. The particular particle the two were interested in detecting is something called an extremely high energy cosmic ray. These particles are far more energetic than anything that even the Large Hadron Collider can produce.

"That means that there's something out there in space," Whiteson says, "some unknown new object in space, that's capable of generating particles at a very, very high energy."

Physicists would dearly love to figure what's producing these energetic particles, but they are very rare. Researchers estimate that, in any century, only one particle falls on a given square kilometer of Earth.

That's where the smart phone comes in. Whiteson and his pals are building an app that turns the CMOS chip in the phone's camera into a particle detector. They're hoping millions of people all over the globe will download the app.

When a high energy cosmic ray hits the top of Earth's atmosphere, it creates a shower of new energetic particles. "So if we have a bunch of users nearby each other, all running the app, they will all see hits in their phone; they'll see particles being detected by our app in their phone in the same moment," says Whiteson. And by analyzing the distribution of the particle shower detected by the phones, Whiteson says, the astrophysicists will learn more about the high energy cosmic ray that produced the shower. That's the idea, anyway.

..."We don't yet know if it's the best idea we ever had, or the silliest idea that we ever had," he says. "But one thing we do know is, it's one of the funnest to work on."